Knitting machine and method of knitting



Oct. 1, 1946.

N. H. SMITH mun-Ins lmcnnm Am) METHOD 'oF mum-me Filed Oct. 21, 1944[Mm/Tar: MJPMHH 5H1] Patented Oct. 1, 1946 KNITTING AND METHOD OFKNITTING Norman H. Smith, Pawtucket,

Hemphill Company, Central Falls,

R. 1., assignor to R. 1.,- a cor-'- poration of Massachusetts IApplication October 21, 1944, Serial No. 559,775

' 4 Claims. (01. 66-14) This invention relates to a new and usefulimprovement in knitting machines of the type having two axially opposedneedle cylinders and to a method of knitting upon this type of machine.More specifically, this invention relates to sinkers associated with thelower cylinder and adapted to cooperate with the needles in the drawingof yarns and to a novel manner of operating these sinkers to carry outthe method.

Two cylinder machines of this type are widely employed for knitting truerib fabric and also knitting a combination of true rib and plain fabric.For the knitting of plain fabric the lower cylinder only is utilized andsinkers are associated therewith to enable the needles to draw yarn andto knit loops.

Heretofore the yarn has been drawn in the throats of the sinkers. Theresult of this is that when the sinkers move to cast off knitted loopsfrom the needles they necessarily act not only upon the knitted loopsbut also upon the yarn which has just been drawn. This yarn iscomparatively unstable at this time so that any lack of uniformity inthe sinkers or the needles or in their actual or relative motions isreflected in the lengths of the loops. Also there is likely to be a lackof uniformity in the shapes of the loops, one side differing from theother or whole loops tilting from the perpendicular.

By the method of'this invention the loops are drawn over the backs ofsinkers behind the nibs on a surface having a definite height.Thereafter the loops are transferred from the backs to the throats ofthe sinkers overthe tops of the nibs. In this way, the casting off isaccomplished by the sinkers acting upon the completed and comparativelystable loops of the preceding course. The newly drawn loops, being onthe backs of the sinkers behind the nibs and able to move freely uponthem, take no part in the casting off operation and are unaffectedthereby.

Also when the sinker loops pass over the nibs on their way to thethroats of the sinkers they are stretched slightly so that the adjacentneedle loops are tightened around the needles. This has an equalizingeffect upon the needle loops. When the needles go down to knit thesinker loops undergo a similar equalizing experience as the needle loopsare stretched by their passage over the enlargedportion of the needlesadjacent the latch pivots.

All of these things, particularly thecasting off of needle loops by theaction of the sinkers upon the sinker loops only, cause improvement inthe quality of the fabric as a whole and of the individual loops whichisvery marked.

1 One'form of the invention is shown in the drawing of which:

Fig. 1 is an elevation largely in section of a part of a two cylinderknitting machine showing the upper end of the lower cylinder, a needlearranged to operate therein, a sinker and the sinker cam;

Fig. 2 is a similar view showing the needle and sinker in a differentposition; and

Figs. 3 and 4 are views illustrating the method of knitting in which theyarn is drawn over the backs of the sinkers.

In Fig. 1 the upper end of the lower cylinder is shown at l. Affixed tothis is an arcuate sinker guide 2 upon which an arcuate sinker 3 isadapted to rock radially of the cylinder. The rocking of sinker 3 iscontrolled by a cam 4 having a cam track 5 of appropriate shape to rocksinker 3 in the desired directions and to the desired extent at thedesired times.

In order to draw the yarn over the backs 6 of the sinkers the sinkersare moved in soon enough and far enough for the purpose. This is shownin Fig. 1, the newly drawn sinker and needle loops being indicated at land 8, respectively. As will be seen, the corresponding sinker loop 9 ofthe preceding course is in the throat of the sinker. Consequently, whenthe sinkers move in still further to cast off the adjacent needle loop10 it will act upon sinker loop 9 only, the newly drawn sinker loop 1upon the back 6 of the sinker being unaffected. To insure sinker has noeffect upon loop l, back 6 is shaped to an arc concentric with the arethrough which the sinker rocks.

Fig. 2 shows a, further step in the knitting operation after the needlehas risen again. The new needle loop 8 has now moved from thehook to theshank of the needle but the adjacent sinker loop 1 is still over theback of the sinker.

Fig. 3 also illustrates this condition, two sinker loops 1 being shownover cent sinkers and around the shank of the intervening needle H.Loops 9 are in the throats of the sinkers, the needle loop [0 havingbeen previously cast off.

Fig. 4 illustrates a further step in the method of knitting in which thesinkers have been moved out so that the new sinker loops 1 have beentransferred from the backs to the throats of the sinkers over the topsof the nibs prior to drawing more yarn over the backs of the sinkers foranother course.

This method of knitting is hardly necessary for that this motion of theg the backs of two adjathe comparatively heavy coarse gauge fabricsordinarily produced upon two cylinder independent needle knittingmachines but is practically essential for the production of fine gaugefabric of the highest grade and for securing the best possible platingand wrap patterns. Drawing the yarns or yarn over the backs of thesinkers makes it possible to apply methods for plating and for theproduction of wrap patterns which cannot be taken advantage of when thethroats of the sinkers are used and which are essential the adjacentsinker loops only and transferring the newly drawn loops from the backsto the throats of the sinkers over their nibs.

2. For a knitting machine of the superposed, co-axial cylinder,independent needle type, a sinker adapted to move in an arcuate pathrelative to the cylinders and having a yarn drawing surface behind thenib shaped to an arc concentric with said path.

3. For a knitting machine of the superposed, coaxial cylinder needletype, a sinker adapted to swing about a center and having a yarn drawingsurface behind the'nib shaped to an are concentric with said center.

4. For a knitting machine of the superposed, coaxial cylinder needletype, a sinker adapted to swing in a vertical plane about a center andhaving a yarn drawing surface behind the nib so shaped that every pointwhen positioned to be contacted by a yarn will be at the same heightwith respect to said cylinder.

NORMAN H. SMITH.

